Power electronics devices are often utilized in high-power electrical applications, such as inverter systems for hybrid electric vehicles and electric vehicles. Such power electronics devices include power semiconductor devices such as power insulated-gate bipolar transistors (IGBTs) and power transistors thermally bonded to a metal substrate. With advances in battery technology and increases in electronics device packaging density, operating temperatures of power electronics devices have increased and are currently approaching 200° C. Heat sinking devices may be coupled to the power electronics devices to remove heat and lower the maximum operating temperature of a power semiconductor device. Cooling fluid may be used to receive heat generated by the power semiconductor device by convective thermal transfer, and remove such heat from the power semiconductor device. For example, a jet of cooling fluid may be directed such that it impinges a surface of the power semiconductor device. Another way to remove heat from a power semiconductor device is to couple the power semiconductor device to a finned heat sink made of a thermally conductive material, such as aluminum.
However, as power electronics devices are designed to operate at increased power levels thereby generating more heat due to the demands of newly developed electrical systems, conventional heat sinks are unable to adequately remove sufficient heat to effectively lower the operating temperature of the power electronics devices to acceptable temperature levels. Further, conventional heat sinks and cooling structures require additional bonding layers and thermal matching materials (e.g., bond layers, substrates, thermal interface materials). These additional layers add substantial thermal resistance to the overall assembly and make thermal management of the electronics system challenging.
Accordingly, a need exists for alternative power electronics assemblies and power electronics devices having internal cooling structures.